Brakes not bleeding

patriot07

Member
Now that the belt problem is fixed, the last issue with my trailmaster XRS mid is the brakes. Previous owner said he replaced the caliper and master cylinder but still can't get the brakes to bleed. I have replaced pads on cars a bunch of times, but don't really know that much about the system...any idea where to start?

Thanks in advance for the help.
 
Now that the belt problem is fixed, the last issue with my trailmaster XRS mid is the brakes. Previous owner said he replaced the caliper and master cylinder but still can't get the brakes to bleed. I have replaced pads on cars a bunch of times, but don't really know that much about the system...any idea where to start?

Thanks in advance for the help.
Most common oversight is putting the caliper on upside down and having the bleeder at the bottom
 
Save yourself some trouble get a veteranary syringe a small hose and reverse bleed ie : pump it through from the bleeder .
Its a bit messy but works .
As stated the bleeder on top .
 
Loosened the bleeder valve and pumped the brake - no fluid coming out. Reservoir is full. Not sure if messing with bleeding is the problem or if I have an actual mechanical issue somewhere...previous owner suspected debris in the hose...maybe?

I checked those 2 links flattop - thanks
 
Ok, so I got the harbor frieght vacuum pump and it didn't pull anything but air. I decided to just take the line off the caliper and pump the brakes and nothing came out. The master cylinder the previous owner said is new. Is it possible there is something lodged in the line? Is that a thing?

Is the only way to find out to pull the line off the cylinder and pump to see if anything comes out?
 
You could pull the line and use a low pressure air gun through the line to see if you feel air. What brake fluid are you using?
 
You could pull the line and use a low pressure air gun through the line to see if you feel air. What brake fluid are you using?
The cap on the cylinder said dot 3 so that's what I got, but I haven't put any in - only what the previous owner had. The reservoir is filled to the top and hasn't dropped at all.

I'll give that idea a try though - thanks.
 
Likely has an air lock in the master cylinder.
Bench bleeding is usually recommended.

Remove line/s at master cylinder, hold finger over outlet/s and slowly press and release brake pedal, until fluid and no air force finger off. May need to remove finger while depressing pedal, then plug before releasing.

May need to lift front of kart to help get air from master cylinder.

After get airlock out of master, reconnect lines.

Open bleeder/s on caliper. With front still lifted, leave set for 30 minutes
Fluid should gravity into caliper.

If you still have trouble getting the last bit of air out, try leaving everything closed , front still lifted, depress pedal slightly, hold for short time, then release.

If you have cap off reservoir, you may see/ hear air bubble inside.
Repeat until see no more air.

These are the things that worked for me.
 
Make sure the brake rod is not holding the caliper open at all when the pedal is back. If the caliper does not go all the way back it can prevent fluid from going from the reservoir to the line.
I think this is the problem. The brake pedal stop definitely doesn't allow a full reset of the cylinder.

I pulled everything apart yesterday. Blew air through the line and it's fine. Pumped cylinder by hand and it's shot out fluid. But it's not getting full travel via the pedal...is it likely he bought the wrong cylinder? Or is there a trick to getting it primed and then it'll work fine? I don't see a p/n on the cylinder so I don't have a way to verify...

Thanks all for the help.
 
You likely will not necessarily need full stroke of master cylinder after getting it bled.
However, it must come completely back to home position every time. Otherwise, if you get it bled, and the temperature rises, trapped fluid will expand and keep brakes engaged.
 
You likely will not necessarily need full stroke of master cylinder after getting it bled.
However, it must come completely back to home position every time. Otherwise, if you get it bled, and the temperature rises, trapped fluid will expand and keep brakes engaged.
So how do I get it bled in this situation? I'm getting nothing out of the back of the hose with the cylinder mounted/installed and the hose attached. I left the back end of the kart elevated all night and the reservoir level didn't drop at all....
 
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